Kyocera FS-1016MFP

2G4
2-3-1
2-3 Operati on of the PWBs
2-3-1 Power source PWB
Figure 2-3-1Power source PWB block diagram
The power source PWB consists of the switching regulator section that is the main part, other zero cross signal detection
circuit and heater lamp control circuit. The switching regulator circuit consists of the noise filter circuit, rectification smooth-
ing circuit, switching control circuit, 5 V DC rectification/smoothing output circuit, 24 V DC rectification/smoothing output
circuit and overvoltage detection circuit, and this circuit converts the AC power input to the 5 V DC and 24 V DC power
source by the switching operation and outputs it to the engine/high voltage PWB. The zero cross signal detection circuit
detects the 0 V point (zero cross) of the AC wave form and outputs to the engine/high voltage circuit, and the engine/ high
voltage PWB outputs the heater lamp ON signal (HEATN) to the heater lamp control circuit based on the timing of zero
cross signal (ZCROSS) and controls the AC power loading to the heater lamp.
F1
F2
SW1
NTC1
AC
input
Power
switch
D32D31
C8
Q1
Noise
filter
circuit
(L1)
Power source PWB
Rectification
smoothing circuit
D10-13
TRA1
PC1
PC2
PC3
PC4
Switching
control
circuit
Heater
lamp
control
circuit
Zero cross
signal
detection
circuit
Pulse
Thermal
cutout
Heater
lamp
PC5
HEATN
24V2
ZCROSS
SLEEP
EXITN
24 V DC
rectification/
smoothing
output circuit
5 V DC
rectification/
smoothing
output circuit
Overvoltage
detection
circuit
(IC101)
Exit
sensor
24V1
5V
GND
GND
T1